code: def test_log_mel_equal():
      layer1 = LinearSpectrogram(n_fft=4, hop_length=1)
      layer2 = LogMelFbank(n_fft=4, hop_length=1, n_mels=2)
      x = torch.randn(2, 4, 9)
      y1, y1_lens = layer1(x, torch.LongTensor([4, 3]))
      y2, _ = layer2(x, torch.LongTensor([4, 3]))
      y1_2, _ = layer2.logmel(y1, y1_lens)
      np.testing.assert_array_equal(
          y2.detach().cpu().numpy(),
          y1_2.detach().cpu().numpy(),
      )
  
file_path: espnet/test/espnet2/tts/feats_extract/test_linear_spectrogram.py
imports: import numpy
  import torch
  from espnet2.tts.feats_extract.linear_spectrogram import LinearSpectrogram
  from espnet2.tts.feats_extract.log_mel_fbank import LogMelFbank
label_desc: Use image node_id 6 for calling a global function with example usage: test_log_mel_equal() without return types